Blue trisazo dye.



UNITED STATES PATENT OFFICE.

ORS TO THE FARBENFABRIKEN YORK.

OFELBERFELD COMPANY, or NEW BLUE Tm sAzo DYE.

SPECIFICATION forming part of Letters Patent No. 658,897, dated October 2, 1900.

Application filed July 20, 1900. Serial No. 24,293. (No specimens.)

To all whom, it may conceive:

Be it known that we, ADOLF ISRAEL and RICHARD KOTHE,doctors of philosophy,chemists, (assignors to the FARBENFABRIKEN or ELBERFELD COMPANY, of New York,) residing at Elberfeld, Germany, have invented a new and useful Improvement in Trisazo Dyes; and we hereby declare the following to be a clear and exact description of our invention.

Our invention relates to the production of valuable trisazo dyestuif, having the general formula:

H are rm; 0 4\SOSH P s Inthis formula the group X-N:N meansa radical of a diazo compoundas, for instance, diazobenzene, paraoxydiazobenzene, paraamidodiazobenzene,diazotized sulfanilic acid, diazotizer paraamidosalicylic acid, diazotized amidosuli'osalic'ylic acid, or the likeY a hydrogen atom which may be substituted by a sulfo group,'and R a hydrogen atom which may be substituted by an alkyl radical.

We point out specifically that We intend to denote 1n the following specification by the term alkyl radical, as well fatty radicals, as aromatic radicals, and radicals of a similar chemical behaviorsuch, for instance, as

the radical of the acetic acid having the formula CH OOOH.

The new process consists in,first,combining a diazo derivative with one molecule of Oleves alphanaphthylaminbetasulfouic acids,(l.6 or 1.7;) secondly, rediazotizing the resulting amidoazo compound and combining the diazo derivative thus obtained with a second molecule of one of the said Cleves acids; thirdly, again diazotizing the resulting amidodisazo dyestuff, and, finally, coupling the diazo compound thus produced with beta -amido-alpha -naphthol beta -sulfonic acid, or with alkyl derivatives thereof. In case the first or the last component causes a sufficient solubility of the dyestufi the two molecules of Cleves acids can also be replaced once or twice by alpha-naphthylamin.

It may be remarked that if in the abovedefined process, for instance, acetylparaphenylenediamin or the like is employed as (beta first component the acetyl group can be split off in a suitable manner after the preparation of the dyestulf.

The dyestuffs produced in the above-defined manner are dark powders having a metallic luster, which dissolve in water with from red= dish-blue to blue color. danted cotton in general blue shades (these shades varying from reddish blue to green ish blue) and are distinguished by their fastness to light.

In carrying out our new process practically we can proceed as follows, the parts being by weight: fifteen parts of acetylparaphenylenediarnin are diazotized in the usual manner with the aid of forty parts of hydrochloric acid (exhibiting 15 Baum) and seven parts of sodium nitrite. The resulting diazo solution is stirred into a solution prepared from twenty-five parts of the sodium salt of ()lves alphanaphthylaminbetasulfonic acid, (1.6,) twenty parts of crystallized sodium acetate, and five hundred parts of water, which solution has been cooled to 10 centigrade. the formation of the dyestuff has been finished the latter is separated from the mixture by the addition of common salt and isolated by filtration. The coloring-matter thus obtained is carefully mixed with five hundred parts of water and then with fifty parts of a hydrochloric acid of 15 Baum. The result ing mixture is cooled and then slowly mixed with a solution of nine parts of sodium nitrite. When the diazotation has been finished, the separated diazo compound is filtered oif. Subsequently itis mixed with a suitable quantity of water and introduced into a watery solution of twenty-five parts of the sodium soar will be finished. This dyestuff is separated with the aid of common salt and filtered ofi. Subsequently it is carefully mixed with wa- Aftel They dye unmorter and fifty parts of a hydrochloric acid of l 15 Baum. To the resulting mixture asolution of nine parts of sodium nitrite is slowly added, while stirring and cooling. The diazo compound thus produced is isolated by filtration, mixed with water, and then stirred into an icy-cold solution of twenty-four parts of beta,-amido-alpha naphthol beta -sulfonic acid, and thirty-five parts of sodium carbonate (CO Na in five hundred parts of water. The so produced trisazo dyestuif is completely salted out by means of common salt,

and is a dark powder having a metallic luster which is readily soluble in water with a pure blue color, the free dyestuif sulfonic acid being recipitated therefrom by the addition of mineral acids. It is soluble with diificulty in alcohol, and it is dissolved by concentrated sulfuric acid (66 Baum) with a greenish-blue color, which is changed into pure blue on the addition of a small quantity of ice, while on the addition of a larger quantity of ice the dyestuff is precipitated again.

The new coloring-matterdyes unmordanted cotton clear-blue shades which are fast to light.

The process proceeds in an analogous manner if, in the above example, in the first position other diazo compounds are employed, or if in the center position alpha -naphthylamin-beta -sulfonic acid is replaced either once or twice by alpha,-naphthylamin-beta -sulfonic acid, and, as above mentioned, in some cases by alpha-naphthylamin. In the last position beta amido-alpha naphthol-beta sulfonic acid can also be replaced, as hereinbefore pointed out, by alkalized or alphylized derivatives.

filtered OE, and pressed. The dyestuff is then dissolved in one thousand parts of water, which solution is mixed with one hundred and fifty parts of a strong alkaline soda lye (containing thirty-three per cent. of NaOH) and boiled for a short while. Finally one hundred and eighty parts of common salt and one hundred and fifty parts of hydrochloric acid of 15 Baum are added. The resulting precipitate is filtered ofi, pressed, dried, and pulverized. It is the sodium salt of an acid having the formula SO H NH, (beta N=N-C, H OH (alpha SO H (beta l Having now described our invention and in what manner the same is to be performed,

.what we claim as new, and desire to secure by Letters Patent, is

1. As new articles of manufacture the new trisazo dyestuffs which are alkaline salts of acids having the general formula:

which in the form of the sodium salt is a dark powder having a metallic luster, readily soluble in water with a pure-blue color, the free dyestufi sulfonic acid being precipitated therefrom by the addition of mineral acids; soluble with difficulty in alcohol; being dissolved by concentrated sulfuric acid (66 Baum) with a greenish-blue color which is changed into pure blue on the addition of a small quantity of ice, while on the addition of a larger quantity of ice a dark precipitate is obtained; dyeing unmordanted cotton clearblue shades which shades are distinguished by their fastness to light, substantially as hereinbefore described.

In testimony whereof we have signed our names in the presence of two subscribing witnesses.

ADOLF ISRAEL. RICHARD KO'lI-IE.

Witnesses:

OTTO KONIG, F. A. KITTERSHAUS. 

